Frame support for a panel



March 28, 1961 E. F. TONEY FRAME SUPPORT FOR A PANEL 4 Sheets-Sheet 2 Filed Dec. 5, 1957 FIG. 6

INVENTOR. {0174M TONI) March 28, 1961 E. F; TONEY 2,976,970

FRAME SUPPORT FOR A PANEL Filed Dec. 5, 1957 4 Sheets-Sheet 5 4 ave/var INVEN TOR. 6'00480 E 700%? United States Patent() i FRAME SUPPORT FOR A PANEL Edward F. Toney, Pittsburgh, Pa., assignorto Pittsburgh Plate Glass Company, Allegheny County, Pa., a .corporation of Pennsylvania Filed Dec. 5, 1957, Ser- No. 700,891

17 Claims. (Cl. 189-75) This invention relates to a building curtain wall construction and more especially relates to a support as part of a supporting structure for glass windows and spandrels in the skin construction for buildings, commonly known as curtain-wall construction.

In the development of a curtain wall for buildings, it has been customary heretofore to provide a frame support for the glass panels and spandrels that uses a glazing compound between the glass panels or spandrels and the frame support to prevent ingress of rain water. The glazing compound must be properly applied in the inital installation and this requires a substantial amount of labor. Furthermore, upon aging of the glazing compound, it has been found necessary to periodically inspect the glazing compound for cracks that develop therein and to applyadditional glazing material as required. When rain water enters between the frame support and the glass windows, the water will be apparent usually inside the building and thereby will call attention to the fact that the application of new or additional glazing compound is necessary. In the meantime damage inside the building may have occurred. When the rain water penetrates between the spandrel panel and the frame support therefor, it can do substantial damage before its presence has been discovered. The water back of the spandrel panel will be at least partly vaporized and the moisture-laden air can provide substantial damage in that area, including deterioration of any coating on the inside surface of the spandrel panel.

One object of the invention is to provide a building curtain wall construction particularly suited to the mounting of glass panels and having improved means for drainage and ventilation of areas behind the panels and a recessed setting for the glass panels.

It is an object of the present invention to provide a frame support for a panel in which the frame support has a construction that can minimize the ingress of rain water without the use of a glazing compound except at the butt joints of vertical and horizontal framing members and at expansion joints. I

It is another object of this invention to provide a frame support for windows and spandrels that minimizes the ingress of rain water without substantial use of a glazing compound and the frame support has a construction that will direct any rain water that has penetrated back of the window or spandrel in a manner to flow it outwardly. I

It is a further object of the present invention to provide a frame support that in addition to minimizing ingress of rain water without substantial use of a glazing compound there is provided ventilation' behind the spandrel panel.

These and other objects of this invention will be apparent to one skilled in the art from the description which follows when taken in conjunction with the drawings of preferred embodiments of this invention in which similar parts are designated by the same numerals and in which: Fig. 1 is a fragmentary elevation of a curtain wall for a building showing a number of glass windows and span- -dre1.panels mounted by the frame supports of the in- :vention;

"ice

2 v Fig. 2 is a vertical cross section taken along the line 2-2 of Fig. 1;

Figs. 3, 4 and 5 are isometric views, partly in sectio and partly broken away, of preferred embodiments of the channel member that is part of the frame support and that supports the glass windows and spandrel panels and cooperates with other parts of the frame support, as shown in Fig. 2, to prevent movement of the windows and panels 'in a direction normal to the faces thereof;

Fig. 6 is a fragmentary horizontal cross section of th curtain wall taken along the line 6-6 of Fig. 1 and showing the construction of the vertical support members that are constructed for horizontal expansion of the wall;

Fig. 7 is a fragmentary horizontal cross section taken slightly above the base of the curtain wall showing the construction of one of the other vertical framing members, that provide support for the glass sheets and spandrels, with the framing member secured to bottom horizontal framing members bolted to the base of the building;

Fig. 8 is a fragmentary vertical cross section at the top of the curtain wall;

Fig. 9 is an enlarged fragmentary cross section of a marginal portion of a window or a spandrel panel with a tape applied to the marginal surfaces and its relationship to parts of the frame support;

Fig. 10.is a fragmentary vertical section with parts omitted and taken along the line 10-10 of Fig. 1 showing a gasket of sealing compound that is applied at the junk:- tion of the horizontal and vertical channel members;

Fig. 11 is a fragmentary vertical section through the vertical and horizontal tubes of the supporting frame showing the modification of the horizontal tubes at one end of the curtain wall;

Fig. 12 is an enlarged fragmentary isometric view, partly in section and partly broken away, of the channel member, channel strip, and the channel snap-on cover in their relative positions for supporting and retaining the windows or spandrel panels;

Fig. 13 is a fragmentary vertical section of the bottom of the curtain wall;

Fig. 14 is an enlarged fragmentary isometric view, partly in section and partly broken away, of another preferred embodiment of the channel member, assembled with the channel strip and the channel snap-on cover in their relative positions for supporting and retaining the windows or spandrel panels;

Fig. 15 is a fragmentary vertical cross section taken along the line 15-15 of Fig. 1 showing another embodiment of the horizontal channel member in combination with other components of the frame support for the glass sheets and spandrels;

Fig. 16 is a fragmentary horizontal cross section taken along the line 16-16 of Fig. 1 showing another embodiment of the vertical channel member in combination with other components of the frame support for the glass sheets and spandrels; i Figs. 17, 18 and 19 are fragmentary vertical cross sections, like Fig. 15 also taken along line 15-15 of Fig. 1, of'other embodiments of the horizontal channel member or division bar in combination with other components of the frame support forthe glass sheets and spandrels; and 7 Figs. 20 and 21 are fragmentary vertical cross sections, like Fig. 15 also taken along the line 15-15 of Fig. l, of additional embodiments of the horizontal division bar with the retainer channel secured to it by screws and show modifications of the Walls of the longitudinal groove in the intermediate flange of the bar of Fig. 19.

As seen in Fig.1 the wall curtain for a building comprises horizontal rows of windows 20 and horizontal rows of spandrel panels 21 supported and maintained in position by a building curtain wall construction forming-a Patented Mar. 28, 1961 i structural grid to frame such windows and panels. The structural grid includes horizontal framing members or grid forming elements generally indicated at 22 and vertical framing members or grid forming elements generally indicated at 23 and 24.

The basic supporting framework for the curtain wall has sets of vertically extending rectangular tubes 26 adjacent one side of the basic building structure. The sets of rectangular tubes 26 are horizontally spaced apart. At intervals along the side of the basic building structure there is used instead of a set of rectangular tubes 26 a set of pairs of opposed vertically extending channel members 27. The bottom tube 26 of a set of rectangular tubes 26 issecured to the base 28 of the building as described blow. The top portion of bottom tube 26 is also secured by means of an angle iron and anchor bolt (not shown) to a masonry 30 or a structural beam (not shown) forming part of a floor of the basic structure of the building. Another tube 26 of that set of tubes is secured by an angle iron (not shown) to masonry 30 or the same structural beam or another structural beam (not shown) forming part of the same floor to which the upper part of the bottom tube 26 is secured so that the bottom end of the second tube is positioned slightly above the top end of the bottom tube 26. The top portion of the second tube 26 is secured to masonry 36 or a structural beam (not shown) forming part of a floor above the first-mentioned floor. The other tubes 26 of the set are likewise secured to masonry 30 or structural beams of successively higher floors so that all of the tubes 26 of a set are in vertical alignment.

For each set of pairs of opposed channel members 27, the bottom pair of members 27 is secured to the base 28 as described below for the bottom tubes 26. The top part of the bottom pair of channel member 27 is each secured by means of angle iron 31, bolt 32 and anchor bolt 34 secured in masonry 30 or a structural beam (not shown). Each of angle irons 31 has a flange 38 that contains a slot 39. Slot 39 receives anchor bolt 34 for securing angle iron 31 to masonry 30. The slot 39 extends horizontally so that angle iron 31 can move relative to bolt 34. The other flange 41 of each angle iron 31 has a vertical slot 42 for receiving bolt 32 welded to channel member 27. Thus bolt 32 will move in slot 42 with expansion of contraction of channel member 27. The other pairs of opposed channel members 27 of the set are mounted in vertical alignment above the bottom pair of channel members 27. These pairs and the top portion of the bottom pair of channel members 27 are secured to flanges 41 of angle irons 31 having their flanges 38 bolted to masonry 30 or to structural bcams (not shown).

Channel members 46 are secured by screws 47 to tubes 26 and to the pairs of opposed channel members 27 For any set of tubes 26 or any set of pairs of opposed channel members 27 the channel members 46 on each side are vertically spaced as shown in Fig. 2.

The basic supporting framework for the curtain wall has, in addition to such. sets of vertically extending rectangular tubes 26, horizontal rectangular support tubes 56 which extend between two sets of tubes 26 or between a set of tubes 26 and a set of pairs of opposed channel members 27. The inside surfaces of the top and bottom walls of tubes 50 at their ends engage the top and bottom surfaces of flanges 52 of channel members 46. The tubes 50 are secured to channel members 46 by screws 53. By this construction there is formed a supporting framework for the curtain wall in which the supporting framework comprises sets of vertical tubes 26 and sets of pairs of opposed channel members 27 and between the sets there are mounted the horizontal support tubes 50.

To form this framework for the curtain wall, a horizotnal support tube 50 is secured to the base 28 of the building by means of longitudinally spaced anchor bolts 54 that extend upwardly through apertures in the bottom wall of tube 50. Through apertures 55 of the top wall of tube 50 are placed washers 56 and nuts 57. The apertures 55 are sufficiently large so that a tool can be inserted for securing nuts 57 to bolts 54. The bottom tube 26 of the corner set of vertical tubes 26 is positioned so that a channel member 46 secured by screws 47 on one of the walls is moved into the end of tube 50. Screws 53 are used to secure channel member 46 to tube 50. The top part of tube 26 is secured by a flange and anchor bolt (not shown) to masonry 30. The other tubes 26 of the corner set are secured to masonry 30. The rest of the support tubes 50 of the set adjacent the corner are brought into position and secured to channel members 46 on the corner set of tubes 26. The next set of tubes 26 or a set or pair of opposed channel members 27 are positioned at the other ends of the first set of tubes 50 and secured thereto as well as secured to masonry 30. The bottom tube 50 of the next set of tubes 50 is secured to base 28 by anchor bolts 54. The other tubes 50 of the set are secured to the second set of tubes 26 or to one of each pair or set of opposed channel members 27 when the latter is used. This process of construction is continued to complete one wall of the building. Of course, when all four sides of a building are to be provided with a curtain wall in accordance with this invention, the fourth wall has a set of tubes 26 that to start the first wall were secured to the building structure and to the adjacent bottom tube 50 of the first wall. This set already has secured thereto the channel members 46 to receive the last set of horizontal tubes 50 for the fourth wall. To move this last set of tubes 50 into position it is necessary to notch out that end of the tubes 50 so that the tubes can be positioned relative to channel members 46 for securing thereto. To accomplish this, these tubes 50 have the construction at one end as shown in Fig. 11 in which one wall is cut back to provide an end 58 and is provided with notches 59 to clear the installed channel member 46 and screws 47. It will be apparent that either the front or the back wall can be shortened at one end and notched as described so that the tube 50 can be moved into position and then secured to channel member 46. Of course, both ends of these and other support tubes 50 may have a wall modified as shown in Fig. 11 and described above.

Referring to Fig. 2, an integral channel member 60 is mounted by screws 61 to the front wall of horizontal support tube 50. The channel member 60 extends the full length of tube 50. Instead of using a support tube 50 there can be used a channel member generally indicated at 63 having a web 64 and flanges 65 and having longitudinal flanges 66 extending from the free ends of flanges 65 and toward each other to provide a structure that would be obtained by removing a longitudinal portion from the front wall of support 5%). The alternate channel member 63 is shown at the top of Fig. 2 and support tube 50 shown at the bottom of Fig. 2. Each provides a flat backup support for integral channel member 60.

Three of the preferred forms of the integral channel member 60 are shown in Figs. 35. The integral channel member. 60 has flanges 68 and 69 and web 70. An intermediate longitudinal portion of web 79 extends forwardly as flanges 72 and 73 that extend substantially beyond flanges 68 and 69; The flanges 72 and '73 are normal to the back surface of web 70 that contacts flanges 66 of channel member 63 or contacts tube 50. The flanges 72 and 73 are joined by a web 74 to provide an inverted U-shaped longitudinal intermediate portion extending outwardly, i.e., to the left as viewed in Fig. 2, with respect to the main portion of web 70. Longitudinal flanges 76 and 77 extend from the free ends of flanges 68 and 69 and have flat outside surfaces parallel to the back surface of web 70. A longitudinal flange 30 extends laterally from web 74 and the front face of flange 80 is parallel to the back surface of web 70 and is in a plane below the front face of web 74. Notches 81 are provided in web 74. The web 70 extends laterally to provide a longitudi- .and 103 and toward each other.

nal flange 82 adjacent flange 68. Theweb 70 between flanges 68 and 72 and between flanges 69 and 73 has apertures 83 for receiving screws 61 to secure channel member 60 to tube 50 or channel member 63. The channel member 60 has longitudinally spaced apertures 84 in either flange 68 or flange 69or both flanges 68 and 69. These three possible constructions are shown in Figs. 3-5, in which the apertures 84 are shown in the preferred form, i.e., as rectangular apertures 84 that are adjacent web 70. The web 74 has longitudinally spaced threaded apertures 85 for receiving screws 86. As shown in Figs. 2-5 the base of notches 81 are preferably coplanar with the front surface of flange 80. Preferably, the flange 80 has a rear surface that curves forwardly at the bottom portion to meet the front face.

A retainer channel 90 (Fig. 2) having a web 91 and flanges 92 and 93 is secured by screws 86 to each channel member 60. In the construction shown in Figs. 2, 8 and 9, the retainer channel 90 has flanges 92 and 93 that are of substantially uniform thickness. The flanges 92 and 93 have outer surface portions adjacent web 91 that are convexly diverging and then concavely converging. At the free ends of flanges 92 and 93 are integral longitudinal flanges 94 and 95 that extend from the free ends of flanges 92 and 93 in opposite directions and have flat rear surfaces that are parallel to and spaced from the front faces of flanges 76 and 77 when retainer channel 90 is secured to integral channel member 60 by screws 86. By this construction, glass panels 20 or spandrel panels 21 can be secured between flanges 76 and 94 or flanges 77 and 95. The web 91 of retainer channel 90 has apertures 98 (Fig. 12), preferably horizontal slots, that are located so that the top edge of aperture 98 is above the top surface of web 74 and the bottom edge is below said surface. The channel 90 is preferably resilient.

Each of the retainer channels is provided with a snapon cover channel 100 having a web 101 presenting a flat outer face parallel to the curtain wall panels and flanges 102 and 103 as well as longitudinal integral flanges 104 and 105 extending from the free ends of flanges 102 The flanges 104 and 105 engage retainer channel 90 in the external grooves provided by flanges 92 and 94 and provided by flanges 93 and 95. The flange 103 has longitudinally spaced apertures 106. The retainer channel 90 has longitudinally spaced apertures 107 in flange 93 in the portion containing the diverging outer surface and the converging surface. The apertures 107 extend into web 91, i.e., apertures 107 are in the portion of flange 93 having an internal trough. I

In these preferred embodiments, the apertures 84 in flange 68 or flange 69 or both are not in alignment vertically with one another or with apertures 98, notches 81, apertures 107 or retainer channel 90, or apertures 106 of snap-on cover channel 100, which are also in misalignment vertically, although for purposes of illustrating with arrows the air flow for ventilation behind a spandrel panel 21 apertures 84, 106, and 107 are shown in alignment in Fig. 2 with one another and with notch 81.

In order to provide a flrm grip by channel member 60 and retainer channel 90 on glass windows 20, the latter is provided at its margins and edges with a tape 110, such as ordinary black friction tape, as shown in Fig. 9. This construction also prevents the glass window from creeping or moving relative to the channel member 60 and retainer channel 90. A similar construction can be used for the spandrel panel and this is especially preferred when the spandrel is a glass sheet, such as a colored glass or a glass sheet having a colored enamel or paint on the rear surface. Of course, spandrels can be panels of other materials, e.g., metal panels.

In the construction shown in Fig. 2, the spandrel panel 21 is thicker than the glass windows 20. In this illustration the forward dimension of flanges 72 and 73 is chosen so that the flanges 94 and 95 are spaced the proper distance from flanges 76 and 77 when retainer channel 90 is secured to channel member 60 to support and retain spandrel panel 21. Because flanges 76 and 77 are in the same vertical plane, flange 76 in the top installation and the flange 77 in the bottom installation are spaced too far from flanges 94 and 95, respectively, to abut glass panels 20. To provide a proper backup by flange 76 or flange 77, a filler strip 111, e.g., a neoprene (synthetic rubber) strip, with a longitudinal groove is placed so that the groove is engaged by flange 76 or flange 77 and the front surface of strip 111 engages glass window 20.

Referring to Fig. 2, showing a vertical section of the curtain wall construction of the invention and the construction back of the spandrel panel 21,.treated wood setting blocks 115, spaced horizontally and resting on tube 50 supporting spandrel panel 21 are covered with a metal flashing 116 that has a longitudinal flange 117 extending downwardly and in front of flange 82 of integral channel member 60. The flashing 116 is bent to provide at its rear an upward flange 118 and the free end of flange 118 is bent in a rear direction to provide a flange 119 that is secured in masonry 30 of the floor substructure for one of the stories of the multi-story building. The flashing 116 has upwardly turned side flanges 122 that abut tubes 26 at one side and tubes 26 or channel members 27 at the other side of flashing 116. Between the upturned side flanges 112 of flashing 116 is a pad 124 of heat-insulating material, such as a pad of glass fibers, provided on the back surface with a vapor-barrier coating (not shown). The pad 124 is adhered by a mastic layer 125 to masonry 30.

The lower glass window 20 is at one story of the building and the upper glass window 20 of Fig. 2 is at the level of the next story above. When tubes 50 and channel member 65 are visible to persons within the building, they can be covered as shown in Fig. 2. For example, a longitudinal sheet 130 having a reentrant flange 131 is sup ported by the plaster ceiling 132 and secured to the underside of tube 50 by screws 133. Likewise the exposed surface of channel member 63 can be covered by a longitudinal cover plate 134 having a reverse flange 135 held by screws (not shown) and at the back side having downwardly extending flange 136 having at its free end a forwardly extending-flange 137 engaged by clip 138 screwed to web 64.

The windows 20 and spandrel panels 21 are mounted at their bottom edges on longitudinally spaced setting blocks 140 resting on flange 72.

Referring to Fig. 8 which shows the mounting of a window 21 at the top story of the building, the snap-on cover 100 and retainer channel 90 are used. An integral channel member 142 secures retainer channel 90 and has flanges 76 and 77 and other structure of channel member 60 but does not need and does not have a flange 82. Furthermore, the flange 68 of channel member 142 does not have an aperture 84. The flange 69 also does not have apertures 84 but if the top panel of the curtain wall is a spandrel panel, then to provide ventilation therebehind, the flange 69 has apertures 84. The flange 76 of channel member 142 and flange 94 of retainer channel 90 secure a longitudinal metal angle member secured to the roof 145 of the building. The forward end of member 144 is supported by a flashing 146. A caulking compound 147 is placed between flange 102 of snapon cover 100 and angle member 144.

Referring to Fig. 7, an integral channel member 150, like channel members 60 and 142, but without flanges and 82, notches 81 and apertures 84, is secured to vertical tube 26 by screws 61. A retainer channel member without apertures 98 and 107 is secured by screws 86 to channel member 150 for engagement of flanges 76, 77, 94 and of channel members 90 and 150 at the vertical margins of glass windows 20 at the floor level or spandrel panels 21 between the floor levels. The snapon cover channel without apertures 106 is in engage- 7 ment with retainer channel 90. For any set of vertical tubes 26 a set of channel members 150, a set of retainer channels 99 and a set of snap-on cover channels 166 are required. The lengths of these various units are so chosen that the junctures of channel members 15b, the junctures of retainer channels 911 and the junctures of snap-on cover channels 100 are in different horizontal planes from one another and from the horizontal planes of the junctures of tubes 26. The portions of vertical tubes 26 at the building level between -a floor and ceiling can be provided with snap-on covers 151.

Where the pairs of opposed channel members 27 are used, channel members 150, retainer channels 90 and snap-on cover channels 180 are not used. Instead a channel member 153 having a web 154 is secured by screws 61 to the front flange 155 of each channel mem ber 27. The channel member 153 has flanges 157 and 158. A longitudinal flange 159 extends from the free end of flange 157 and extends toward flange 158. The flange 158 extends forwardly a substantial distance beyond flange 159 and has longitudinally spaced threaded apertures 160 near its free end for receiving screws 161. Longitudinal E-shaped members 162 are secured by screws 161 to flanges 169. One of the outermost flanges 163 of E-shaped members 162 has longitudinally spaced threaded apertures 164 by which a channel member 165 is secured to one of flanges 163 and abuts the front face also of the other flange 163. At the levels where channel members 27 can be seen from within the building, the channel members 27 can be covered by covers 166 and 167. A plate 168 is secured to flange 169 of one of channel members 27 and also abuts the rear flange '169 of the other channel member 27 of a pair. By this means, channelmember 165 and plate 168 maintain a cover front and rear, respectively, of this assembly during any movement of the pair of channel members 27 toward or away from each other. The glass windows 20 or spandrel 21 are maintained in position between flanges 159 and E-shaped members 162. To prevent ingress of water between windows 20 or spandrels 21 and E-shaped members 162, a glazing compound 17% is installed therebetween. Likewise, as shown in Fig. 6, a strip of glazing compound 171 is placed between and in contact with flanges 155 of channel members 27 and flanges 158 of channel members 153.

At the junctures between channel members 61} and channel members 150 or 153, there is placed therebetween a gasket 174 of sealing compound (Fig. 10).

Referring to Fig. 13 showing the use of a channel member 60 of Fig. along with retainer'channel 9i and snap-on cover channel 190 for the bottom portion of a curtain wall, flanges 77 and 95 of channel member 61) and retainer channel 90, respectively, are used to support and retain a Z-shaped bar 150 so that it is spaced above a flashing 181. The tube 59 is mounted on the base 23 of the building but supported thereabove by setting blocks 182 mounted on flashing 181. A longitudinal strip of caulking compound 153 is placed below tube 50 to prevent passage of moisture between tube 50 and flashing 181. By this construction any water, that enters between channel 61) and retainer channel 90 or between channel 90 and snap-on cover channel 169 and finds its way back of bar 180, passes out aperture 84 of flange 69 and flows between flashing 131 and bar 180 to the outside for drainage.

Referring to Fig. 14, an integral channel member 192' has flanges 191 and 192 and a web 193. An intermediate longitudinal flange 195 extends forwardly from Web 193 between flanges 191 and 192. Longitudinal flanges 196 and 197 extend from the free ends of flanges 191 and 192, respectively, and have flat front surfaces parallel to the back surface of web 193. The longitudinal flange 196 extends away from intermediate flange 195 and longitudinal flange 197 extends toward intermediate flange 195. A longitudinal flange '198 extends laterally from the top of web 193. The flanges 191, 196 and 198 form a trough 199.

The channel member 190 can be used, for example, in place of integral channel member 60 in the construction shown in Fig. 2. In this instance the channel member 190 would be mounted by screws 61 to the front wall of horizontal support tube 50. For mounting channel member 190 to support tube 50 the web 193 has apertures 200 longitudinally spaced on both sides of flange 195. The flange 198 in channel member 190 prevents water on the top surface of flange 191 from flowing behind channel member 190 and thus flange 198 functions in the manner as flange 82 in the channel member 60 shown in Figs. 3, 4 and 5. The flange 196 functions as a backing member for a glass sheet or spandrel and thus functions in the same way as does flange 76 of channel member 60 shown in Figs. 3, 4 and 5. It is noted that flange 196 is upwardly turned when channel member 190 is mounted in the horizontal position whereas flange 76 of channel member 69, when mounted in the horizontal position as in Fig. 2, is downwardly turned. Because flange 196 is upwardly turned, i.e., it is joined at its bottom to flange 191 of channel member 190, the width of web 193 of channel member 19% is reduced so that flange 198 is directly behind flange 196. Thus the presence of flange 198 for the purpose mentioned above does not decrease the effective viewing area of the glass panel or window 20, whereas in the construction of channel member 6!) flange is above flanges 76 and 68 so that it reduces the effective viewing area.

The top surface of flange 195 is flat from its juncture with web 193 to its front face. A longitudinal channel or groove 261 is in flange 195 and extends from the front face of flange 195 toward web 193. The top and bottom walls 262 and 203 of groove 281 have longitudinal ribs 2134 and 295, respectively. The ribs 204 are in vertical planes between ribs 205. The walls 262 and 203 in front of ribs 264 and 205 diverge forwardly. The ribs 204 and 265 serve the same essential function as threads in a nut and thus receive screws 2173 which secure retainer channel against the front face of flange 195. As in the embodiment shown in Fig. 12 the embodiment in Fig. 14 has apertures 93 in web 91. The apertures 98 are positioned so that part is opposite a portion of the front face of flange 195 and part is above flange 195. With the construction, water falling onto flange 195 will flow out apertures 98. It is unnecessary to have notches in the front face of flange 195 like notches 81 in the front face of web 74 of channel member. As a matter of fact because of apertures 98, notches 81 are unnecessary in web 74 of channel member 60. i

The flanges 92 and 93 of retainer channel 91) have the construction previously described to provide at their free ends integral longitudinal flanges 94 and 95. The flanges 94- and have flat rear surfaces that are parallel to and spaced from the flat front faces of flanges 196 and 197 when retainer channel 91) is secured by screws 208 to integral channel member 190. Glass panels 29 or spandrel panels 21 can be secured between flanges 94 and 196 or flanges 95 and 197.

ln the construction shown in Fig. 14 in which the integral channel member 199 is used in the horizontal po sition apertures 93 are present to provide water drainage. As in the division bar 60 as shown in Fig. 12 the division bar 191 of Fig. 14 has longitudinally spaced apertures 84 in flange 191 which compares with flange 63 of division bar 61). Likewise, the bottom flange 192 has apertures 94 longitudinally spaced as in bottom flange 69 of integral channel member 69 shown in Fig. 5. The apertures 84 in flanges 191 and 192 and apertures 98 in retainer channel 90 provide for ventilation behind a spanclrel panel 21 as heretofore described in connection with channel member 60. In the event that water passes downwardly between retainer channel 9:; and the front face of flange of integral channel member 19$ the flange 195, at its bottom surface spaced rearwardly from its front face, is provided with a downwardly extending flange 209 that desirably prevents water flowing rearwardly on the bottom surface of flange 195, downwardly on the front face of web 193 and through apertures 84 in flange 192.. The flange 209 is positioned sufliciently forward from web 193 that water dripping from flange 209 falls into the top surface of flange 93 and flows out through apertures 107 in flange 93 and the adjacent portion of web 91 of retainer channel 90.

As described heretofore the retainer channel 90 is provided with a snap-on cover channel 100 having a web 101 and flanges 102 and 103 with integral flanges 104 and 105 extending from the free ends of flanges 102 and 103 and toward each other. The flanges 104 and 105 engage retainer channel 90 as heretofore described. The flange 103 has longitudinally spaced apertures 106 for water drainage and other purposes as previously described.

- Of course, the channel member 190 can be used as a vertical component of the metal frame support for a panel. In this type of use it is unnecessary to have apertures 84, 98 and 107, and 106 in channel member 190, retainer channel 90 and snap-on cover channel 100, respectively. Similarly it is unnecessary to have flange 209 extending from intermediate flange 195. This modified construction is shown in Fig. 16 in which the integral channel member is designated 210. Because the channel member 210 is used in the vertical position, it is unnecessary to have a construction to provide a trough similar to trough 199 in the channel member 190 of Fig. 14. Thus the integral channel member 210 has a web 211 and the flanges 212 and 213 extending forwardly. From the forward ends of flanges 212 and 213 extend flanges 214 and 215, respectively. An intermediate flange 216 extends forwardly from web 211. Neither of the vertical walls 217 and 218 of flange 216 need be flat from front to rear. Thus intermediate flange 216 is thinner atits portion adjacent web 211. Water cannot accumulate in these troughs. The flange 216 has a longitudinal groove 201 with the same construction as the groove 201 of integral channel member 190. A screw 208 secures retainer channel 90 against the front face of flange 216. The flanges 94 and 95 of retainer channel 90 have their rear faces abutting the front marginal surfaces of panels 20. On the opposite rear surfaces of windows 20 are flanges 214 and 215, respectively. A snap-on cover 100 engages retainer channel 90 as heretofore described in connection with other embodiments.

The integral channel member 210 has longitudinally spaced apertures 219'in web 211 on each side of flange 216. The integral channel member 210 is secured to vertical support tube 26 by screws 61 when channel member 210 is used instead of channel member 150.

Referring to Fig. 15 an integral channel member generally indicated at 220 has the same construction as integral channel member 190 except that intermediate flange 195 of channel member 190 is replaced by an intermediate flange 222. The flange 222 has flat horizontal top and bottom surfaces. A flange 209 extends from the bottom surface of intermediate flange 222 as flange 209 extends from the bottom surface of intermediate flange 195 of integral channel member 190. The intermediate flange 222 is provided with a longitudinal groove 223. The width of the groove is greatest intermediate its front and rear portions. In the construction shown in Fig. 15 this is accomplished by providing one longitudinal rib 224 on each of the top and bottom walls of groove 223 with ribs 224 being positioned adjacent the front face of flange 222. Rearwardly of the widest portion of groove 223 the top and bottom wall portions 225 of groove 223 converge rearwardly. A number of internally threaded members 226 having a pair of parallel sides are placed in groove 223 between ribs 224 and converging wall portions 225. The members 226 are spaced longitudinally in groove 223 with the parallel sides opposing the walls of the groove so that members 226 are in alignment with apertures longitudinally spaced in the central axis of web 91 of retainer channel 90. Screws through these apertures are threaded into members 226 and secure web 91 of retainer channel against the front face of intermediate channel 222, so that flange 94 opposes flange 196 to hold window 20 between them and flange 95 opposes flange 197 to hold panel 21 between them. The Window 20 rests on setting blocks 14, as described above, which rest in this embodiment on the top surface of flange 222.

Referring to Fig. 17 an integral channel member 230 has the same construction as integral channel member 190 except that intermediate flange 195 of channel member 190 is replaced by an intermediate flange 231 which has a flat horizontal top surface. Depending from flange 231 are spaced apart downwardly extending flanges 232 and 233, the latter being rearward of the former, with longitudinally spaced apertures 234 and 235, respectively. An aperture 234 is in alignment with an aperture 235. Snap-0n nuts or screw fasteners 236 are placed on flange 233 with their apertures in alignment with apertures 235. Screws 208 engage arched prongs 237 of each of fasteners 236 and secure retainer channels 90 against the front face of flange 231. Channel 230 and retainer channel 90 secure window 20 on setting blocks and panel 21 as heretofore described for other embodiments. In view of the construction of the embodiment of Fig. 17 With flanges 232 and 233 a flange like flange 209 of other embodiments is not necessary.

Referring to Fig. 18 an integral channel member 240 also has the same construction as integral channel member except that intermediate flange of channel member 190 is replaced by an intermediate flange 241 with a longitudinal groove 242 that is wider at its base to prevent forward movement of a number of longitudinally spaced internally threaded members 243, each of which has a pair of parallel sides that are flared outwardly at their rear whereby forward movement of members 243 in groove 242 is prevented. Screws 208 are threaded in members 243 to secure retainer channel 90 against the front face of intermediate flange 241 so that channels 90 and 240 secure window 20 on blocks 140 and panel 21 as heretofore described. A flange 209 extends from the bottom of flange 241 as in other embodiments.

Referring to Fig. 19, an integral channel member 250' has the same construction as integral channel member 190 except that intermediate flange 195 of channel mem-- ber 190 is replaced by an intermediate flange 251 having a longitudinal groove 252. As in other embodiments of a horizontal channel member the top surface of intermediate flange 251 is flat and supports window 21 on it with the use of setting blocks 140. From the bottom surface depends flange 209. Longitudinally spaced screws- 253, such as sheet metal screws, bite into the top and bot-- tom walls of flange 251 in groove 252 which has the necessary width for this purpose. Flange 250 is also provided with a longitudinal rib 254 in each of the top and bottom walls of groove 252 adjacent its front. The ribs 254 engage screw 253 for guidance purposes and thus are in different vertical planes. The screws 253 se cure retainer channel 90 against the front face of intermediate flange 251 for the purpose previously described for other embodiments.

In Fig. 20 the integral channel member 260 is identical with integral channel member 250 of Fig. 19 except that the former has an intermediate flange 261 instead of flange 251 in the latter. The flange 261 has a longitudinal groove 262. The top and bottom walls of flange 261 in groove 262 have longitudinal ribs 254. In addition the bottom wall has longitudinal ribs 264 rearwardly of rib 254. The width of groove 262 is determined so that screws 253, as in groove 252 of channel member 250, will bite into the top wall of channel member 260 in its groove 262' as well as engage ribs 264 in the bottom wall and are if positioned initially by ribs 254. The flange 209 extends downwardly from flange 260 as in other embodiments.

In Fig. 21 the integral channel member 270 is also identical with integral channel member 250 of Fig. 19 except it has an intermediate flange 271 instead of flange 251. The flange 271 has a longitudinal groove 272. The top wall of the groove 272 is smooth, i.e., free of ribs. The bottom wall has longitudinal rib 254 near the front of the wall and ribs 264 behind rib 254. Screws secure retainer channel 90 against the front face of flange 271 by engaging rib 25 i and ribs 264 as well as by biting into the top wall of groove 272. The flange 209 depends from flange 270 as in other embodiments.

The horizontal framing members 22 comprise tubes 50 or channel members 63, channel members 60, 142, 190, 230, 240, 250, 260 or 270, retainer channels 90, snap-on cover channels 160, and associated parts. The vertical framing members 23 comprise tubes 26, channel members 150 or 210, retainer channels 9h, snap-on cover channels 100, and associated parts. The vertical framing members 24 comprise pairs of channel members 27, channel members 153, E-shaped members 162, channel members 165 and associated parts. As shown in Figs. 2 and 7 the side surfaces of the superposed support tubes, channel memher and cover channel are coplanar, forming with the outer face of the cover channel and the rear face of the support tube, a tubular envelope and giving the effect of tubular framing members with the panels recessed in the sides of the members.

The various integral channel members, such as channel members 60, 210 and 250, can be made of extruded metals such as extruded aluminum. The tubes 50 can be square or can be of any other rectangular configuration. The tubes 50 will have dimensions such that the front faces of flanges 155 of channel members 27 will be coplanar with the front faces of tubes 50. The snap-on covers 100 for use in the vertical direction can have longer flanges 102 and 103 than those of cover channels 1% used in the horizontal position. This is shown in Fig. 2.

When rain water strikes window or spandrel 21, the water runs down the front face thereof. Most of the water flows outwardly along the top surface of flange 102 of horizontal snap-on cover channel 100. However, some of the water flows between window 20 and flange 94 of retainer channel 90. This water drops on the top surface of flange 72 or web 74. Rearward flow is prevented by web 70. The water flows forwardly and then through notches 81, i.e., between channel member 60 and retainer channel 90. When apertures 98 are present in retainer channel 90 and notches 81 are absent, water from the top surface of web 74 flows through apertures 98 and then flows downwardly on the front face of retainer channel 90. When both notches 81 and apertures 98 are present in the construction for channel members 60 and 90, respectively, some of the water flows through apertures 98 and some flows through notches 81. Water flowing through notches 81 reaches drip flange 80, the front face of which is in vertical alignment with the internal trough provided by web 91 and flange 93. The water in the trough flows through apertures 107. Water flowing through apertures 98 or apertures 107 falls onto the inside of top surface of flange 103 of snap-on cover channel 100 and flows to the outside through apertures 106.

Any moisture that condenses on the inside surface of window 20 flows to the bottom marginal portion of window 20. Part of the water may flow between window 20 and. flange 76 and fall on the top surface of flange 72 and then flow through apertures 98 or notches 81 as described above. Water builds up on the top surface of flange 68 and flows through apertures 84 to reach the top surface of flange 72. The rearward movement of the water on flange 68 is prevented by flange 82.

Similarly, any moisture that condenses on the rear sur-= face of spandrel panel 21' flows through apertures 84 of flange 68 of channel member 60 at the bottom portion of panel 21. This water flows to the outside of the curtain wall by means of notches 81 or apertures 98 and apertures 106. Of course, when notches 81 are used for part of the water flow, apertures 107 in retainer channel member are also utilized.

The apertures 84, 98, 106 and 107 and notches 81 permit the entrance of outside air to the space behind panel 21. The air flows upwardly in the space behind panel 21 and then flows through apertures 84 in flange 69 and out apertures 106 and 107 of the assembly of channel members 60 and 90 and cover channel 100 immediately above panel 21. From the foregoing it will be seen that ventilation with outside air of the space immediatelybehind panel 21 is obtained. The air flow is shown by arrows in Fig. 2.

The integral construction of the various channel members, such as channel members 60 and 250, provide for support for window 20 or spandrel panel 21. For example, when using channel member 60 flanges 76 and 77 provide backup members for window 20 and panel 21. In addition, web 74 provides for support for retainer channel 90 which has flanges 94 and 95 that maintain window 20 or panel 21 against flanges 76 and 77. At the same time, the integral channel member 60 has a structure that insures that any water passing between flange 94 and window 20 or panel 21 will be directed outwardly of the assembly of channel members 60 and 90 and cover channel rather than flow in a manner to reach the area back of window 20 or panel 21. Thus channel member 60 cooperates with retainer channel 90 and snap-on cover channel 100 in a unitary way to prevent ingress of rain water and at the same timeto permit ventilation of the space behind a spandrel panel 21.

The invention has been illustrated in connection with a curtain wall for a building and its use in other construction, such as store front construction, will be apparent.

This application is a continuation in part of my copending application Serial No. 649,417 entitled Frame Support for a Panel and filed on March 29, 1957, now abandoned.

Many modifications of the structure of the curtain wall components described above and shown in the drawings will be apparent to one skilled in the art. The foregoing description and drawings are merely illustrative of preferred embodiments and are presented not by way of limitation to the invention which is to be limited solely by the claims which follow.

I claim:

1. In a frame support for a panel, an integral channel member comprising a web having flat rearmost surface portions, a pair of flanges extending forwardly from the web with at least one of said flanges having 'a flat outside surface normal to said flat rearmost surface portions of said web and forming with the adjacent longitudinal edge of the web a flat surface substantially devoid of projections, longitudinal flanges extending angularly from said pair of forwardly extending flanges with each having a flat surface at the most forwardly extending portion of its front face, said flat surfaces being parallel to each other and to said flat rearmost surface portions of said web, and a flange extending forwardly from the web between said pair of flanges, spaced from said longitudinal flanges and having a front face parallel to and substantially forward of said flat front surfaces of said longitudinalflanges.

2. In a frame support for a panel, an integral channel member comprising a web having flat rearmost surface portions, top and bottom flanges extending forwardly from the web with at least one of said top and bottom flanges having a flat outside surface normal to said flat rearmost surface portions of said web and formingwith the adjacent longitudinal edge of the web a flat surface substantially devoid of projections, a first longitudinal flange extending angularly from the bottom flange at its free end, a second longitudinal flange extending angularly from the top flange at its free end, said longitudinal flanges having front faces parallel to said flat rearmost surface portions of said web, an intermediate flange extending forwardly from the web to provide a front face parallel to and substantially forward of the parallel front faces of said longitudinal flanges, said intermediate flange being spaced from said longitudinal flanges, and a longitudinal drip flange extending downwardly from said intermediate flange in a plane forwardly of the front face of said first longitudinal flange.

3. In a frame support for a panel, an integral channel member comprising a web having flat rearmost surface portions, top and bottom flanges extending forwardly from the web with said bottom flange having a flat outside surface normal to said flat rearmost surface portions of said web and forming with the adjacent lon-, gitudinal edge of the web a flat surface substantially devoid of projections, a first longitudinal flange extending normal to the bottom flange at its free end, a second longitudinal flange extending angularly from the top flange at its free end, said longitudinal flanges having front faces parallel to said flat rearmost surface portions of said web, an intermediate flange extending forwardly from the web to provide a front face parallel to and substantially forward of the parallel front faces of said longitudinal flanges, said intermediate flange being spaced from said longitudinal flanges, and a 1ongitudi-' nal flange extending upwardly from the top of the web and forming with the top flange a gutter along the upper. edge ofthe channel member, at least one of the top and bottom vflanges of the channel member having longitudinally spaced apertures. 4. The integral channel member of claim 3 and further including a longitudinal drip flange extending downwardly from said intermediate flange in a plane forwardly of the front face of said first longitudinal flange.

5. In a frame support for a panel, an integral channel membercomprising a web having flat rearmost surface portions, top and bottom flanges extending forwardly normal to the web with said bottom flange having a flat outside surface normal to said flat rearmost surface portions of said web and forming with the adjacent longitudinal edge of the web a flat surface substantially devoid of projections, a first longitudinal flange extending upwardly normal to the bottom flange at its free end, a second longitudinal flange extending up wardly from the top flange at its free end and forming with the top flange a gutter along the upper edge of the channel member, said longitudinal flanges having front faces parallel to each other and to said flat rearmost surface portions of said web, an intermediate flange extending forwardly from the web to provide a front face parallel to and substantially forward of the parallel front faces of said longitudinal flanges, said intermediate flange being spaced from said longitudinal flanges and having a longitudinal groove extending rearwardly from the front face of the intermediate flange to receive longitudinally spaced screws, a longitudinal flange extending upwardly from the top of the web, and a longitudinal drip flange extending downwardly from said intermediate flange, said drip flange being substantially forward of said first-longitudinal flange, and said top flange having longitudinally spaced apertures. t 6. In a frame support for a panel, an integral channel member comprising a web having flat rearmost surface portions, top and'bottom flanges extending forwardly normal to the web with at least one of said top and bottom flanges having a flat outside surface normal to said flat rearmost surface portions of said web and forming with the adjacent longitudinal edge of the web '14 first longitudinal flange extending angularly from the bottom flange at its free end, a second longitudinal flange extending angularly from the top flange at its free end, said longitudinal flanges having front faces parallel to each other and to said flat rearmost surface portions of said web, an intermediate flange extending forwardly from the web, a third longitudinal flange extending normal to the intermediate flange at its free end to provide a front face parallel to and substantially forward of the parallel faces of said first and second longitudinal flanges and having longitudinally spaced apertures, a fourth longitudinal flange extending normal to the intermediate flange intermediate the third longitudinal flange and the web and having longitudinallyspaced apertures in alignment with the apertures in thethird longitudinal flange, said intermediate flange extending forwardly from the web being spaced from the first and second horizontal flanges.

7. A metal frame support for a panel comprising the integral channel member of claim 1 and further including an integral channel strip having a web, and a pair of rearwardly extending flanges, and longitudinal flanges extending laterally at the free ends of the pair of flanges extending rearwardly from the web of the channel strip and having rear faces, each with a flat surface portion extending most rearwardly and parallel to, opposing and spaced from the parallel front surface of the front faces of the longitudinal flanges of the channel member with the rear face of the web of the channel strip abutting the front face of the flange extending forwardly from the web of the integral channel member between the pair of flanges of said channel member.

8. The channel member of claim 1 with both of said pair of flanges having a flat outside surface normal to said flat rearmost surface portions of said web and wherein the flange extending forwardly between said pair of flanges and spaced from-said longitudinal flanges has a retainer fastener aperture extendingrearwardly from its front face.

' 9. In a frame support for a panel, an integral channel member including a web having flat rearmost surface portions, .top. and bottom flanges extending forwardly from the web with said bottom flange having a flat outside surface normal to said flat rearmost surface portions of said web and forming with the adjacent longitudinal edge of the web a flat surface substantially devoid of projections, a longitudinal flange extending upwardly from the top of the web and forming with the top flange a gutter along the upper edge of the channel member, at least one of said top and bottom flanges having longitudinally spaced apertures, a first longitudinal flange extending normal to the free end of the bottom flange, a second longitudinal flange extending angularly from the free end of the top flange, said first and second longitudinal flanges each having a flat surface at the most forwardly extending portion of its front face, said flat surfaces of said longitudinal flanges being parallel to each other and to said flat rearmost surface portions of said web, the web having a longitudinal portion extending forwardly to provide a front longitudinal face parallel to and substantially forward of said flat front surfaces of said first and second longitudinal flanges, and a longitudinal, drip flange extending downwardly from said forwardly extending web portion and rearwardly of said front longitudinal face, said drip flange being substantially forward of said first longitudinal flange and said forwardly extending longitudinal portion of the web being spaced from said first and second longitudinal flanges;

10. In metal frame support for a panel comprising the integral channel member of claim 8 and further including an integral channel strip having a web, a pair of flanges extending rearwardly, and longitudinal flanges extending laterally at the free ends of the pair of flanges of the a flat surface substantially devoid of projections, a channel strip and having rear faces parallel to, opposing and spaced from the parallel front faces of the longitudinal flanges extending normal to the pair of flanges of the channel member, with the rear face of the web of the channel strip abutting the front face of the flange extending forwardly from the web of the integral channel member between the pair of flanges of said channel member.

11. A metal frame support for a panel comprising the integral channel member of claim and further including an integral channel strip having a web having apertures longitudinally spaced therein and top and bottom rearwardly extending flanges, screws in said apertures of said channel strip and secured in the groove in the intermediate flange of the integral channel member whereby the web of the channel strip abuts the front face of the intermediate flange of the channel member, said integral channel strip having longitudinal flanges extending laterally at the free ends of the top and bot-- tom flanges of the channel strip and having rear faces parallel to, opposing and spaced from the parallel front faces of the longitudinal flanges of the channel member, and said web having additional longitudinally spaced apertures having bottom edges below and top edges above the top surface of the intermediate flange of the channel member.

12. A metal frame support for a panel comprising the integral channel member of claim 5 and further including an integral channel strip having a web, a pair of rearwardly extending flanges with longitudinal convex outer surface portions and adjoining rearward longitudinal concave outer surface portions extending to the free ends of the pair of flanges of the channel strip, and longitudinal flanges extending laterally away from each other from the free ends of said pair of flanges of the channel strip to provide by said combination of convex and concave surface portions and said lateral flanges of said channel strip a pair of longitudinal grooves in the front face of the channel strip, said lateral flanges of said channel strip having parallel flat rear faces, screws longitudinally spaced and securing the web of said channel strip in abutting relationship with the front face of the intermediate flange of the channel member with said screws extending into the groove of said intermediate flange, said rear face of the lateral flanges of the channel strip being parallel to, opposing and spaced from the parallel front faces of the longitudinal flanges of the channel member, and a channel snap-on cover having a web, a pair of flanges rearwardly extending normal to the web and longitudinal flanges at the free ends of the pair of rearwardly extending flanges of the channel snapon cover with the longitudinal flanges toward each other for engagement with the longitudinal grooves in the front face of the channel strip.

13. In a frame support for a panel, an integral channel strip having a web, a pair of rearwardly extending flanges having longitudinal convex outer surface portions and adjoining rearward longitudinal concave surface portions extending to the free ends of the pair of flanges of the channel strip, and longitudinal flanges extending laterally away from each other from the free ends of said pair of flanges of the channel strip to provide by said combination of convex and concave surface portions and said lateral flanges of said channel strip a pair of longitudinal grooves in the front face to receive a channel snap-on cover on the channel strip, said lateral flanges of said channel strip having parallel flat rear faces.

14. A building curtain wall construction forming a structural grid to frame rectangular curtain wall panels, said structural grid comprising perpendicularly arranged grid forming elements adapted to be anchored to the outside of the building, each grid forming element carrying: spaced panel backing members forwardly of the opposite side edges thereof, an intermediate retainer supporting flange projecting forwardly of said panel backing members, an elongated retainer strip providing a panel retainer with each retainer strip rigidly fastened on an opposed intermediate flange and having longitudinal margins on opposite sides of said intermediate flange for clamping adjacent curtain wall panels between each retainer strip and opposed panel' backing members, and a cover channel secured on each retainer strip with each cover channel presenting a flat outer surface parallel to said curtain wall panels; each grid forming element and cover channel carried by said grid forming element having coplanar side surfaces forming with the flat outer surface of the cover channel a substantially tubular envelope providing the effect of a tubular framing member with said curtain wall panels recessed in the sides of the framing members.

15. A building curtain wall construction forming a structural grid to frame rectangular curtain wall panels, said structural grid comprising perpendicularly arranged grid forming elements adapted to be anchored to the outside of the building, each grid forming element carrying: spaced panel backing members forwardly of the opposite side edges thereof, an intermediate retainer supporting flange projecting forwardly of said panel backing members, an elongated retainer strip providing a panel retainer with each retainer strip rigidly fastened on an opposed intermediate flange and having longitudinal margins on opposite sides of said intermediate flange for clamping adjacent curtain wall panels between each retainer strip and opposed panel backing members, and a cover channel secured on each retainer strip with each cover channel presenting a flat outer surface parallel to said curtain wall panels; each grid forming element and cover channel carried by said grid forming element having coplanar side surfaces forming with the flat outer surface of the cover channel a substantially tubular envelope providing the effect of a tubular framing member with said curtain wall panels recessed in the sides of the framing member; and mean including communicating apertures providing a drainage and ventilation course from the inside upper edge of a horizontal framing member through the latter to the lower forward edge of the cover channels of the horizontal tubular framing member, for draining moisture to the outside of said curtain wall panels and ventilating areas behind said panels.

16. A building curtain wall construction forming a structural grid to frame rectangular curtain wall panels, said structural grid comprising perpendicularly arranged grid forming reinforcing elements adapted to be anchored to the outside of the building, each grid forming reinforcing element carrying: a'panel backing channel mounted on the outer face of said reinforcing element, said backing channel comprising a web, marginal flanges carrying spaced panel backing members forwardly of the opposite side edges of said channel web, and an intermediate retainer supporting flange projecting forwardly of said panel backing members; an elongated retainer strip providing a panel retainer with each retainer strip rigidly fastened on the intermediate flanges of an opposed backing channel'and having longitudinal margins on opposite sides of said intermediate flange for clamping adjacent curtain wall panels between each retainer strip and panel backing members on said opposed backing channel; and a cover channel secured on said retainer strip with each cover channel presenting a flat outer surface parallel to said curtain wall panels; each reinforcing element, backing channel, and cover channel carried by said reinforcing element having coplanar side surfaces form ing with the flat outer surface of the cover channel a substantially tubular envelope providing the effect of a tubular framing member with said curtain wall panels recessedin the sides'of the framing member.

17. In a building curtain wall, an improved construc tion forming a structural grid to frame rectangular curtain wall panels, said structural grid comprising perpendicularly arranged grid forming reinforcing elements adapted to be anchored to the outside of the building, and a panel frame comprising vertical backing channels and horizontal backing channels between said vertical backing channels with each backing channel carried on the outer face of one reinforcing element, each backing channel having a web and a pair of flanges extending forwardly from the longitudinal margins of the web with each flange of said vertical backing channels having an outer surface normal to the outer face of said reinforcing elements and forming with the adjacent longitudinal edge of the web a flat surface substantially devoid of projections for receiving the ends of said horizontal backing channels with the latter in abutting relation with the vertical backing channels, means carried by said flanges providing flat panel abutting surfaces, each backing channel having an intermediate flange projecting from the web forwardly of said panel abutting means, an elongated panel retainer strip mounted facing each backing channel on the intermediate flange thereof and having longitudinal margins on the opposite sides of the intermediate flange, means carried by said longitudinal margins of each retainer strip for clamping adjacent panels between said strip and the panel abutting means carried by the adjacent backing channel with the opposing panel edges separated by the intermediate flange thereof, longitudinally spaced screw fastener means extending through each retainer strip and into the opposing intermediate flange of the adjacent backing channel for rigidly securing the strip to the latter, and a cover channel secured on the outer face of each retainer strip.

References Cited in the tile of this patent UNITED STATESPATENTS 1,199,357 Evans I Sept. 26, 1916 1,882,881 Plym Oct. 18, 1932 2,620,525 Ketchum Dec. 9, 1952 FOREIGN PATENTS 636,852 Great Britain May 10, 1950 877,823 Germany May 26, 1953 892,369 Germany Oct. 5, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2 976 97O March 28, 1961 Edward F. Toney It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 15, for "blow" read below line 35 for 'member" read members line 44 "of" read or column 5 line 54 for 'or" first occurrence read of column 8 line 44,, before "portion" insert top column 14 line 27, for "surface" read surfaces Signed and sealed this 22nd day of October 1963.

(SEAL) Attest: EDWIN L, REYNOLDS ERNEST W. SWIDER Attesting Officer Acting COIHIIIISSlOHCr of Patents 

